Accelerated sludge solubilisation under sulphate reducing conditions: the effect of hydrolytic enzymes on sludge floc size distribution and EPS composition
- Akhurst, P, Rose, Peter D, Whiteley, Chris G, Pletschke, Brett I
- Authors: Akhurst, P , Rose, Peter D , Whiteley, Chris G , Pletschke, Brett I
- Date: 2002
- Language: English
- Type: Conference paper
- Identifier: vital:6455 , http://hdl.handle.net/10962/d1010430
- Description: Extracellular polymeric substances (EPS) are the construction materials for microbial aggregates such as biofilms, flocs and sludge, and greatly contribute to the structural integrity of sludge flocs in wastewater treatment processes. The loss of integrity of the sewage sludge floc is believed to be due to enhanced hydrolysis of important structural components such as lignin, protein and cellulose in the sludge floc matrix. The mechanism of enhanced sludge floc fracture, due to the action of enzymes hydrolysing these structural components, remains a key element in our understanding of how the floc integrity in systems utilising a sulphate reducing system is compromised. A range of relatively non-specific exogenous enzymes (ß-glucosidase, cellulase, proteases: trypsin, pronase E and chymotrypsin) were added to a sulphidogenic bioreactor- (containing both sulphate reducing bacteria (SRB) and a methanogenic bacterial system) and a (control) methanogenic bioreactor sample, and the effect of these enzymes on sludge floc size (diameter) distribution and EPS composition was investigated. Sludge samples from the bioreactors were examined under bright field and differential interference contrast light microscopy. Proteolytic and glucohydrolytic activity of the enzymes were monitored using standard enzyme assaying techniques, and Bradford, Somogyi-Nelson, and total carbohydrate assays were performed to establish the composition of the EPS (after extraction with 3% (v/v) glutaraldehyde and Sephacryl S-400 size exclusion chromatography). Sludge flocs present in the sulphidogenic environment of the sulphidogenic bioreactor were found to have smaller diameters than their counterparts present in the methanogenic bioreactor. The addition of hydrolytic (i.e. proteolytic and glycohydrolytic) enzymes resulted in an increased rate of matrix hydrolysis, leading to increased rates of floc fracture and deflocculation. The presence of ß-glucosidase, cellulase, and proteases naturally residing within the sludge floc was confirmed. We propose that the addition of commercially available enzymes may be prohibitively costly on a large scale, and that the activity of the enzymes naturally residing within the floc matrix be optimised or enhanced. As the bulk of the EPS was shown to be composed of mainly polysaccharides, we propose that by increasing the activity of the naturally occurring ß-glucosidases residing within the floc matrix, the process of deflocculation may be enhanced. As sulphide has been shown to increase the activity of this very important key enzyme, we propose that this is one of the contributing factors why sludge solubilisation is accelerated under sulphate reducing conditions.
- Full Text:
- Authors: Akhurst, P , Rose, Peter D , Whiteley, Chris G , Pletschke, Brett I
- Date: 2002
- Language: English
- Type: Conference paper
- Identifier: vital:6455 , http://hdl.handle.net/10962/d1010430
- Description: Extracellular polymeric substances (EPS) are the construction materials for microbial aggregates such as biofilms, flocs and sludge, and greatly contribute to the structural integrity of sludge flocs in wastewater treatment processes. The loss of integrity of the sewage sludge floc is believed to be due to enhanced hydrolysis of important structural components such as lignin, protein and cellulose in the sludge floc matrix. The mechanism of enhanced sludge floc fracture, due to the action of enzymes hydrolysing these structural components, remains a key element in our understanding of how the floc integrity in systems utilising a sulphate reducing system is compromised. A range of relatively non-specific exogenous enzymes (ß-glucosidase, cellulase, proteases: trypsin, pronase E and chymotrypsin) were added to a sulphidogenic bioreactor- (containing both sulphate reducing bacteria (SRB) and a methanogenic bacterial system) and a (control) methanogenic bioreactor sample, and the effect of these enzymes on sludge floc size (diameter) distribution and EPS composition was investigated. Sludge samples from the bioreactors were examined under bright field and differential interference contrast light microscopy. Proteolytic and glucohydrolytic activity of the enzymes were monitored using standard enzyme assaying techniques, and Bradford, Somogyi-Nelson, and total carbohydrate assays were performed to establish the composition of the EPS (after extraction with 3% (v/v) glutaraldehyde and Sephacryl S-400 size exclusion chromatography). Sludge flocs present in the sulphidogenic environment of the sulphidogenic bioreactor were found to have smaller diameters than their counterparts present in the methanogenic bioreactor. The addition of hydrolytic (i.e. proteolytic and glycohydrolytic) enzymes resulted in an increased rate of matrix hydrolysis, leading to increased rates of floc fracture and deflocculation. The presence of ß-glucosidase, cellulase, and proteases naturally residing within the sludge floc was confirmed. We propose that the addition of commercially available enzymes may be prohibitively costly on a large scale, and that the activity of the enzymes naturally residing within the floc matrix be optimised or enhanced. As the bulk of the EPS was shown to be composed of mainly polysaccharides, we propose that by increasing the activity of the naturally occurring ß-glucosidases residing within the floc matrix, the process of deflocculation may be enhanced. As sulphide has been shown to increase the activity of this very important key enzyme, we propose that this is one of the contributing factors why sludge solubilisation is accelerated under sulphate reducing conditions.
- Full Text:
Action research : exploring the use [of] print media as a resource in the teaching of English as a second language
- Authors: Letsoalo, Matome David
- Date: 2002
- Subjects: Action research in education , English language -- Study and teaching -- Foreign speakers
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2376 , http://hdl.handle.net/10962/d1005962 , Action research in education , English language -- Study and teaching -- Foreign speakers
- Description: South African education has been going through a process of transformation: from a traditional, transmission system to one of a more progressive nature. In the new curriculum, Curriculum 2005 anchored on Outcomes-based Education (OBE), focus is laid on critical reflection, innovation and creativity by classroom participants. Learning situations are expected to promote flexibility, co-operation and relevance of teaching/learning materials. This research looks at these aspects in the English Second Language (ESL) situation where print media articles are used as resource. Other than being a rich resource for language, print media texts have been found to be appropriate for this exploration because of their potential to offer opportunities for critical reflection and interaction with authentic issues. Unlike uncritical reliance on textbooks, the proper use of media articles can give the teachers and learners the space to select relevant and exciting materials for their situations. In this study, the research was done through action research where I (the researcher) actually taught the lessons in collaboration with the English teacher. The teaching method was influenced by the Freirean style of Iiberatory teaching where critical reflection, socio-political relevance and co-operation are crucial elements. The action research was done in two cycles. Experiences in the first cycle pointed to, among other aspects, the fact that the learners could not work in a co-operative way as they were not used to it. Addressing this problem consequently became the basis of the second cycle where the skills of co-operative learning were taught before the learners engaged in further lessons. The conclusions drawn from this research point to the importance of the teacher as an agent in the learning process if the demands of progressive and liberatory teaching are to be met. It has thus been concluded that elements such as critical thinking, creativity, flexibility and selection/development of relevant materials presuppose the existence of a well-trained teacher who is skilled and able to make these possible. In the light of my findings, my major recommendation is that teacher development needs to be strengthened so that more emphasis is placed on enhancing the teacher's ability to critique texts and improve his or her own practice, acquiring the skills to teach in a critical way and achieving the learning competencies.
- Full Text:
- Authors: Letsoalo, Matome David
- Date: 2002
- Subjects: Action research in education , English language -- Study and teaching -- Foreign speakers
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2376 , http://hdl.handle.net/10962/d1005962 , Action research in education , English language -- Study and teaching -- Foreign speakers
- Description: South African education has been going through a process of transformation: from a traditional, transmission system to one of a more progressive nature. In the new curriculum, Curriculum 2005 anchored on Outcomes-based Education (OBE), focus is laid on critical reflection, innovation and creativity by classroom participants. Learning situations are expected to promote flexibility, co-operation and relevance of teaching/learning materials. This research looks at these aspects in the English Second Language (ESL) situation where print media articles are used as resource. Other than being a rich resource for language, print media texts have been found to be appropriate for this exploration because of their potential to offer opportunities for critical reflection and interaction with authentic issues. Unlike uncritical reliance on textbooks, the proper use of media articles can give the teachers and learners the space to select relevant and exciting materials for their situations. In this study, the research was done through action research where I (the researcher) actually taught the lessons in collaboration with the English teacher. The teaching method was influenced by the Freirean style of Iiberatory teaching where critical reflection, socio-political relevance and co-operation are crucial elements. The action research was done in two cycles. Experiences in the first cycle pointed to, among other aspects, the fact that the learners could not work in a co-operative way as they were not used to it. Addressing this problem consequently became the basis of the second cycle where the skills of co-operative learning were taught before the learners engaged in further lessons. The conclusions drawn from this research point to the importance of the teacher as an agent in the learning process if the demands of progressive and liberatory teaching are to be met. It has thus been concluded that elements such as critical thinking, creativity, flexibility and selection/development of relevant materials presuppose the existence of a well-trained teacher who is skilled and able to make these possible. In the light of my findings, my major recommendation is that teacher development needs to be strengthened so that more emphasis is placed on enhancing the teacher's ability to critique texts and improve his or her own practice, acquiring the skills to teach in a critical way and achieving the learning competencies.
- Full Text:
Alkane oxidation using metallophthalocyanine as homogeneous catalysts
- Authors: Grootboom, Natasha Denise
- Date: 2002
- Subjects: Oxidation , Alkanes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4449 , http://hdl.handle.net/10962/d1007794
- Description: Iron polychlorophthalocyanine (FePc(Cl)₁₆) and tetrasulfophthalocyanine ([M¹¹TSPc]⁴) complexes of iron, cobalt and manganese are employed as catalysts for the oxidation of cyclohexane using tert-butyl hydroperoxide (TBHP), chloroperoxybenzoic acid (CPBA) and hydrogen peroxide as oxidants. Catalysis using the FePc(Cl)₁₆ was performed in a dimethylformamide:dichloromethane (3 :7) solvent mixture. For the [Fe¹¹TSPc]⁴⁻, [Co¹¹TSPc]⁻ and [Mn¹¹TSPc]⁴⁻catalysts, a water:methanol (1:9) mixture was employed. The products of the catalysis are cyclohexanone, cyclohexanol and cyclohexanediol. The relative percentage yields, percentage selectivity and overall percentage conversion of the products depended on types of oxidant, or catalyst, concentrations of substrate or catalysts and temperature. TBHP was found to be the best oxidant since minimal destruction of the catalyst and higher selectivity in the products were observed when this oxidant was employed. Of the four catalysts investigated [Fe¹¹TSPc]⁴⁻ yielded the highest overall percentage conversion of 20%.The mechanism of the oxidation of cyclohexane in the presence of the FePc(Cl)₁₆ and [M¹¹TSPc]⁴⁻ involves the oxidation of these catalysts, forming an Fe(IlI) phthalocyanine species as an intermediate. Electrocatalysis using [Co¹¹TSPc]⁴⁻ as catalyst, employed an aqueous pH 7 buffer medium for electro-oxidation of 4-pentenoic acid. An enone is suggested as the only oxidation product of 4-pentenoic acid. No degradation of [Co¹¹TSPc]⁴⁻ was observed during the electrocatalytic process. In this process water was used as a source of oxygen therefore eliminating the production of by products from oxidant as in the case of TBHP and CPBA. This system was studied In an attempt to set up conditions for alkane electrocatalytic oxidation.
- Full Text:
- Authors: Grootboom, Natasha Denise
- Date: 2002
- Subjects: Oxidation , Alkanes
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4449 , http://hdl.handle.net/10962/d1007794
- Description: Iron polychlorophthalocyanine (FePc(Cl)₁₆) and tetrasulfophthalocyanine ([M¹¹TSPc]⁴) complexes of iron, cobalt and manganese are employed as catalysts for the oxidation of cyclohexane using tert-butyl hydroperoxide (TBHP), chloroperoxybenzoic acid (CPBA) and hydrogen peroxide as oxidants. Catalysis using the FePc(Cl)₁₆ was performed in a dimethylformamide:dichloromethane (3 :7) solvent mixture. For the [Fe¹¹TSPc]⁴⁻, [Co¹¹TSPc]⁻ and [Mn¹¹TSPc]⁴⁻catalysts, a water:methanol (1:9) mixture was employed. The products of the catalysis are cyclohexanone, cyclohexanol and cyclohexanediol. The relative percentage yields, percentage selectivity and overall percentage conversion of the products depended on types of oxidant, or catalyst, concentrations of substrate or catalysts and temperature. TBHP was found to be the best oxidant since minimal destruction of the catalyst and higher selectivity in the products were observed when this oxidant was employed. Of the four catalysts investigated [Fe¹¹TSPc]⁴⁻ yielded the highest overall percentage conversion of 20%.The mechanism of the oxidation of cyclohexane in the presence of the FePc(Cl)₁₆ and [M¹¹TSPc]⁴⁻ involves the oxidation of these catalysts, forming an Fe(IlI) phthalocyanine species as an intermediate. Electrocatalysis using [Co¹¹TSPc]⁴⁻ as catalyst, employed an aqueous pH 7 buffer medium for electro-oxidation of 4-pentenoic acid. An enone is suggested as the only oxidation product of 4-pentenoic acid. No degradation of [Co¹¹TSPc]⁴⁻ was observed during the electrocatalytic process. In this process water was used as a source of oxygen therefore eliminating the production of by products from oxidant as in the case of TBHP and CPBA. This system was studied In an attempt to set up conditions for alkane electrocatalytic oxidation.
- Full Text:
An analysis of the trawl and longline fisheries for Merluccius capensis off the west coast of South Africa
- Authors: Fairweather, Tracey Pamela
- Date: 2002
- Subjects: Fisheries -- South Africa , Merluccius capensis -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5218 , http://hdl.handle.net/10962/d1005061 , Fisheries -- South Africa , Merluccius capensis -- South Africa
- Description: The South African hake resource faces divergent fishing pressures and management issues. Although the resource consists of two species, management was simplified because the resource was only subject to trawl effort and because of the similarity in population parameters, single species assessment models could be adopted. The impact of trawling on the stock is considered to be well understood and the resource has shown recovery since exclusion of foreign vessels. The 1990s were punctuated by major political change and the need for transformation has resulted in an expansion of the number of fishing rights holders. Longlining has been reintroduced and there is no clear understanding of how the combined fishing pressures will affect the population structure of either Merluccius capensis or M. paradoxus. Information is vital to successful management. Fisheries are complex and intricate, and at times appear impossible to control or monitor. An integrated information system provides easily understood graphical explanations of complex issues. This thesis assessed the dynamics of the trawl and longline fisheries between 1994 and 1999 using a geographical information system (GIS). The accessability of a GIS incorporates the needs of scientists, managers and fishing communities. The simple GIS developed in this study revealed shifts in effort, facilitated the calculation of spatially precise catches and biomasses and highlighted the inadequacy of current sampling coverage. Trawlers were shown to fish the same areas consistently during the years investigated, with highest fishing intensity and average CPUE achieved at depths between 300 and 500m. Analysis of the longline sector revealed several similarities to the trawl sector, fishing intensity was highest between 301 and 500m, suggesting that both sectors face a "friction of distance" dilemma. The distribution and abundance of hake, in particular the exploitable proportion of the population, was determined by a combination of depth and substrate type. The selectivity patterns of trawlers and longliners were briefly investigated with the results illustrating that gear selectivity of the M. capensis stock was depth dependent. The deeper fishing occurred, the larger the length-at-selection. As a result, the M. capensis parental stock faces unprecedented fishing pressure. In the absence of reliable species-specific catch data, logistic and linear regression models were developed to split the hake catch into its respective species components. Large discrepancies between the predicted M. capensis catch for the two models were noted. Regression estimates constructed at a finer spatial scale may provide a better fit than the current depth logistic employed by Marine and Coastal Management. A first attempt at assessing the M. capensis resource on the West Coast using an age-structured production model was presented. It was found that a lengthy and accurate M. capensis catch series is required before it is possible to successfully model the dynamics of the stock. It is necessary to incorporate finer spatial detail in the collation of catch data and collection of sampling data. It would be unadvisable to assume that the stock is stable or recovering. The implications of a size/sex relationship must be investigated and properly appraised.
- Full Text:
- Authors: Fairweather, Tracey Pamela
- Date: 2002
- Subjects: Fisheries -- South Africa , Merluccius capensis -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5218 , http://hdl.handle.net/10962/d1005061 , Fisheries -- South Africa , Merluccius capensis -- South Africa
- Description: The South African hake resource faces divergent fishing pressures and management issues. Although the resource consists of two species, management was simplified because the resource was only subject to trawl effort and because of the similarity in population parameters, single species assessment models could be adopted. The impact of trawling on the stock is considered to be well understood and the resource has shown recovery since exclusion of foreign vessels. The 1990s were punctuated by major political change and the need for transformation has resulted in an expansion of the number of fishing rights holders. Longlining has been reintroduced and there is no clear understanding of how the combined fishing pressures will affect the population structure of either Merluccius capensis or M. paradoxus. Information is vital to successful management. Fisheries are complex and intricate, and at times appear impossible to control or monitor. An integrated information system provides easily understood graphical explanations of complex issues. This thesis assessed the dynamics of the trawl and longline fisheries between 1994 and 1999 using a geographical information system (GIS). The accessability of a GIS incorporates the needs of scientists, managers and fishing communities. The simple GIS developed in this study revealed shifts in effort, facilitated the calculation of spatially precise catches and biomasses and highlighted the inadequacy of current sampling coverage. Trawlers were shown to fish the same areas consistently during the years investigated, with highest fishing intensity and average CPUE achieved at depths between 300 and 500m. Analysis of the longline sector revealed several similarities to the trawl sector, fishing intensity was highest between 301 and 500m, suggesting that both sectors face a "friction of distance" dilemma. The distribution and abundance of hake, in particular the exploitable proportion of the population, was determined by a combination of depth and substrate type. The selectivity patterns of trawlers and longliners were briefly investigated with the results illustrating that gear selectivity of the M. capensis stock was depth dependent. The deeper fishing occurred, the larger the length-at-selection. As a result, the M. capensis parental stock faces unprecedented fishing pressure. In the absence of reliable species-specific catch data, logistic and linear regression models were developed to split the hake catch into its respective species components. Large discrepancies between the predicted M. capensis catch for the two models were noted. Regression estimates constructed at a finer spatial scale may provide a better fit than the current depth logistic employed by Marine and Coastal Management. A first attempt at assessing the M. capensis resource on the West Coast using an age-structured production model was presented. It was found that a lengthy and accurate M. capensis catch series is required before it is possible to successfully model the dynamics of the stock. It is necessary to incorporate finer spatial detail in the collation of catch data and collection of sampling data. It would be unadvisable to assume that the stock is stable or recovering. The implications of a size/sex relationship must be investigated and properly appraised.
- Full Text:
An assessment of the efficacy of two lysine microencapsulation techniques to determine the quantitative lysine requirement of the South African abalone, Haliotis midae L
- Shipton, Thomas A, Britz, Peter J, Walker, Roderick B
- Authors: Shipton, Thomas A , Britz, Peter J , Walker, Roderick B
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184289 , vital:44197 , xlink:href="https://doi.org/10.1046/j.1365-2095.2002.00204.x"
- Description: The quantification of the essential amino acid requirements of a species is a prerequisite to the formulation of biologically optimized diets. In this study, crystalline L-lysine was used in an attempt to determine the quantitative lysine requirement of juvenile Haliotis midae. Two microencapsulation techniques [gelatine/acacia and cellulose acetate phthalate (CAP)] were used to retard leaching of crystalline L-lysine incorporated into semipurified test diets. An assessment of the efficacy of the encapsulation techniques, revealed that despite effective lysine supplementation, H. midae fed semipurified test diets containing encapsulated crystalline L-lysine failed to promote significant improvements in either growth, feed or protein efficiency (P > 0.05). The failure of the crystalline L-lysine to illicit growth and nutritional responses is discussed.
- Full Text:
- Authors: Shipton, Thomas A , Britz, Peter J , Walker, Roderick B
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184289 , vital:44197 , xlink:href="https://doi.org/10.1046/j.1365-2095.2002.00204.x"
- Description: The quantification of the essential amino acid requirements of a species is a prerequisite to the formulation of biologically optimized diets. In this study, crystalline L-lysine was used in an attempt to determine the quantitative lysine requirement of juvenile Haliotis midae. Two microencapsulation techniques [gelatine/acacia and cellulose acetate phthalate (CAP)] were used to retard leaching of crystalline L-lysine incorporated into semipurified test diets. An assessment of the efficacy of the encapsulation techniques, revealed that despite effective lysine supplementation, H. midae fed semipurified test diets containing encapsulated crystalline L-lysine failed to promote significant improvements in either growth, feed or protein efficiency (P > 0.05). The failure of the crystalline L-lysine to illicit growth and nutritional responses is discussed.
- Full Text:
An assessment of the genetic diversity and origin of the invasive weed Chromolaena Odorata (L.) King and Robinson in South Africa
- Authors: Von Senger, Inge
- Date: 2002
- Subjects: Biodiversity -- South Africa , Chromolaena odorata -- Biological control -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4233 , http://hdl.handle.net/10962/d1003802 , Biodiversity -- South Africa , Chromolaena odorata -- Biological control -- South Africa
- Description: Chromolaena odorata (L.) King and Robinson is an alien invasive weed to most of the Old World tropical regions of the earth, including South Africa where it is morphologically distinct from most other C. odorata plants examined from both its native and invasive range. It is thought that these morphological differences are related to difficulties encountered in successful establishment of biological control agents on the South African population of C. odorata. It has been postulated that the source population of the South African population will harbour potential biocontrol agents that will be suited to successful establishment on the South African plants. Several morphological, cytological and isozyme studies have been attempted to identify the source population of the South African population, but these have failed to identify the origin of the South African population. In this dissertation two PCR-based methods were attempted, in an investigation into whether the morphological differences and difficulties in establishment of biocontrol agents have a genetic basis. The two techniques attempted were: Inter Simple Sequence Repeat (ISSR) amplification, and DNA sequencing. Results could not be obtained using the ISSR method, and the reason for this was not discovered despite extensive trials. The internal transcribed spacer region and the external transcribed spacer region sequences were obtained from five samples, and compared. It was found that the ETS region gave more phylogenetic signal at the intraspecific level than the ITS region. However, due to difficulties in amplification of the external transcribed spacer region, work here focussed on obtaining Internal Transcribed Spacer sequences for 61 samples. Each of the samples sequenced had a unique ITS sequence, displaying a high level of intraspecific genetic diversity. The degree of this diversity is discussed with reference to the possible influences of polyploidy and concerted evolution on genetic structure. The ITS data indicated that some of the physical traits used to define ‘morphotypes’ of C. odorata were not correlated to genotype. From discussion and comparison of morphological character distributions and the ITS-based phylogeography it is suggested that the geographical origin of the South African population is Greater Antilelan, rather than from the continents of North and South America, which is where the Australasian, West African and Mauritian infestations are suggested to have originated.
- Full Text:
- Authors: Von Senger, Inge
- Date: 2002
- Subjects: Biodiversity -- South Africa , Chromolaena odorata -- Biological control -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4233 , http://hdl.handle.net/10962/d1003802 , Biodiversity -- South Africa , Chromolaena odorata -- Biological control -- South Africa
- Description: Chromolaena odorata (L.) King and Robinson is an alien invasive weed to most of the Old World tropical regions of the earth, including South Africa where it is morphologically distinct from most other C. odorata plants examined from both its native and invasive range. It is thought that these morphological differences are related to difficulties encountered in successful establishment of biological control agents on the South African population of C. odorata. It has been postulated that the source population of the South African population will harbour potential biocontrol agents that will be suited to successful establishment on the South African plants. Several morphological, cytological and isozyme studies have been attempted to identify the source population of the South African population, but these have failed to identify the origin of the South African population. In this dissertation two PCR-based methods were attempted, in an investigation into whether the morphological differences and difficulties in establishment of biocontrol agents have a genetic basis. The two techniques attempted were: Inter Simple Sequence Repeat (ISSR) amplification, and DNA sequencing. Results could not be obtained using the ISSR method, and the reason for this was not discovered despite extensive trials. The internal transcribed spacer region and the external transcribed spacer region sequences were obtained from five samples, and compared. It was found that the ETS region gave more phylogenetic signal at the intraspecific level than the ITS region. However, due to difficulties in amplification of the external transcribed spacer region, work here focussed on obtaining Internal Transcribed Spacer sequences for 61 samples. Each of the samples sequenced had a unique ITS sequence, displaying a high level of intraspecific genetic diversity. The degree of this diversity is discussed with reference to the possible influences of polyploidy and concerted evolution on genetic structure. The ITS data indicated that some of the physical traits used to define ‘morphotypes’ of C. odorata were not correlated to genotype. From discussion and comparison of morphological character distributions and the ITS-based phylogeography it is suggested that the geographical origin of the South African population is Greater Antilelan, rather than from the continents of North and South America, which is where the Australasian, West African and Mauritian infestations are suggested to have originated.
- Full Text:
An assessment of the impact of the black village communities, their associated land-use and related practices on water quality of the Kat River in the Eastern Cape, South Africa
- Authors: Soviti, Malixole Knottien
- Date: 2002 , 2013-05-16
- Subjects: Water quality -- South Africa -- Kat River , Water -- Pollution -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4810 , http://hdl.handle.net/10962/d1004638 , Water quality -- South Africa -- Kat River , Water -- Pollution -- South Africa -- Eastern Cape
- Description: Amongst others, the South African National Water Act No. 36 of 1998 acknowledges that access to sufficient safe and clean water is a basic right to all South Africans. However, it is well known that millions of inhabitants of rural communities in South Africa are still deprived of this right. Many rural communities in South Africa are thus consuming unsafe, untreated water everyday, thereby exposing themselves to waterborne diseases. The main reason of concern however is the fact that, nevertheless, little is known about rural water quality in South Africa as most water quality work is being undertaken in urban areas. The study's aim is twofold: first, the study examines the impact of Black rural communities' land-use and related activities on water quality and second is specifically, to study the washing practices of the rural communities in the upper Kat River area. To understand the potential impacts of the upper Kat River Black village communities and their associated land-use practices on the quality of upper Kat River catchment, prominent land-use and related activities in the area were investigated. Study area maps were studied and field surveys undertaken to observe major land-use and related activities in the area. The results of the study show that most used land in the area is being utilised for agricultural activities. Settlements and commercial forestry also occupy considerable areas of land. The literature survey suggests that such land-use could have a considerable degrading impact on the quality of both surface and groundwater. The study also investigated the impact of the in-stream use of detergents on water quality in the upper Kat River valley, Eastern Cape - South Africa. In-stream washing practices of certain communities in the upper Kat River valley were investigated and the impact of detergents on water quality was assessed. Recovery of the flow from the input of detergents was also measured. During the study, it has been ascertained that doing laundry by the stream is the common practice in the study area. Water quality analysis results show a remarkable increase on the levels of chloride, turbidity, and electrical conductivity in water as a consequence of direct input of detergents practice into the river during the washing. The recovery of the water quality at a distance of 1km from site of input was almost complete. Water quality monitoring programme was undertaken to establish a link between land-use and the quality of water. In a water quality study routine carried out for a period of 40 weeks on a twice monthly frequency, the state of the flows of the river was determined; water samples were collected at pre-determined points; and the in situ analysis of selected water quality variables (with the exception of the faecal coliforms whose analysis was carried out in the biotechnology laboratory) was carried out. Results of the study showed that the concentration of the studied water quality variables in the area varied widely with time. A clear distinction in concentration of variables such as electrical conductivity, turbidity, pH, total hardness, chloride, and nitrate was evident at the high compared to the low flow period of the study. The concentration of the studied water quality variables in the upper Kat River catchment area also seemed to vary over space. The concentration of variables such as electrical conductivity, pH, total hardness, chloride, nitrate, potassium, number of faecal coliform bacteria per 100ml was observed to be higher in most of the tributary streams than the main river. Turbidity however was orders of magnitude higher in the Kat River than the rest of the tributaries. Most importantly however, results of the study showed that there is a strong link between the quality of water and land-use and related activities in the area. The spatial results of the study showed a strong connection between some land-use and the concentrations of water quality variables. For example, areas of intense grazing were noted with high concentrations of nutrients like nitrate and a higher number of faecal coliform bacteria per 100 ml of water. It was established during the study that land-use and related activities in the upper Kat River valley are negatively impacting on the quality of water thereby rendering it less fit for use for domestic purposes. The continued use of the polluted water by the communities is thus accompanied by a danger of the outbreak of waterborne diseases like cholera. When the concerned communities met in a workshop to discuss the issue of quality of their water, they committed themselves to: • shunning water polluting activities, • at least boiling their drinking water before consuming it. The communities also requested a meeting with the Department of Water and Forestry officials to request a treated, piped supply of water. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Authors: Soviti, Malixole Knottien
- Date: 2002 , 2013-05-16
- Subjects: Water quality -- South Africa -- Kat River , Water -- Pollution -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4810 , http://hdl.handle.net/10962/d1004638 , Water quality -- South Africa -- Kat River , Water -- Pollution -- South Africa -- Eastern Cape
- Description: Amongst others, the South African National Water Act No. 36 of 1998 acknowledges that access to sufficient safe and clean water is a basic right to all South Africans. However, it is well known that millions of inhabitants of rural communities in South Africa are still deprived of this right. Many rural communities in South Africa are thus consuming unsafe, untreated water everyday, thereby exposing themselves to waterborne diseases. The main reason of concern however is the fact that, nevertheless, little is known about rural water quality in South Africa as most water quality work is being undertaken in urban areas. The study's aim is twofold: first, the study examines the impact of Black rural communities' land-use and related activities on water quality and second is specifically, to study the washing practices of the rural communities in the upper Kat River area. To understand the potential impacts of the upper Kat River Black village communities and their associated land-use practices on the quality of upper Kat River catchment, prominent land-use and related activities in the area were investigated. Study area maps were studied and field surveys undertaken to observe major land-use and related activities in the area. The results of the study show that most used land in the area is being utilised for agricultural activities. Settlements and commercial forestry also occupy considerable areas of land. The literature survey suggests that such land-use could have a considerable degrading impact on the quality of both surface and groundwater. The study also investigated the impact of the in-stream use of detergents on water quality in the upper Kat River valley, Eastern Cape - South Africa. In-stream washing practices of certain communities in the upper Kat River valley were investigated and the impact of detergents on water quality was assessed. Recovery of the flow from the input of detergents was also measured. During the study, it has been ascertained that doing laundry by the stream is the common practice in the study area. Water quality analysis results show a remarkable increase on the levels of chloride, turbidity, and electrical conductivity in water as a consequence of direct input of detergents practice into the river during the washing. The recovery of the water quality at a distance of 1km from site of input was almost complete. Water quality monitoring programme was undertaken to establish a link between land-use and the quality of water. In a water quality study routine carried out for a period of 40 weeks on a twice monthly frequency, the state of the flows of the river was determined; water samples were collected at pre-determined points; and the in situ analysis of selected water quality variables (with the exception of the faecal coliforms whose analysis was carried out in the biotechnology laboratory) was carried out. Results of the study showed that the concentration of the studied water quality variables in the area varied widely with time. A clear distinction in concentration of variables such as electrical conductivity, turbidity, pH, total hardness, chloride, and nitrate was evident at the high compared to the low flow period of the study. The concentration of the studied water quality variables in the upper Kat River catchment area also seemed to vary over space. The concentration of variables such as electrical conductivity, pH, total hardness, chloride, nitrate, potassium, number of faecal coliform bacteria per 100ml was observed to be higher in most of the tributary streams than the main river. Turbidity however was orders of magnitude higher in the Kat River than the rest of the tributaries. Most importantly however, results of the study showed that there is a strong link between the quality of water and land-use and related activities in the area. The spatial results of the study showed a strong connection between some land-use and the concentrations of water quality variables. For example, areas of intense grazing were noted with high concentrations of nutrients like nitrate and a higher number of faecal coliform bacteria per 100 ml of water. It was established during the study that land-use and related activities in the upper Kat River valley are negatively impacting on the quality of water thereby rendering it less fit for use for domestic purposes. The continued use of the polluted water by the communities is thus accompanied by a danger of the outbreak of waterborne diseases like cholera. When the concerned communities met in a workshop to discuss the issue of quality of their water, they committed themselves to: • shunning water polluting activities, • at least boiling their drinking water before consuming it. The communities also requested a meeting with the Department of Water and Forestry officials to request a treated, piped supply of water. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
An exploration of functional and numerical flexibility in South African organisations: a qualitative study in two textile factories in Cape Town
- Authors: Sela, Ronit
- Date: 2002
- Subjects: Business enterprises -- South Africa -- Case studies , Industrial management -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:3347 , http://hdl.handle.net/10962/d1006149 , Business enterprises -- South Africa -- Case studies , Industrial management -- South Africa
- Description: During this research, an attempt was made to gain an understanding of management and their employees' perceptions regarding functional and numerical flexibility practices within South African organisations. To achieve this, twenty-six people, comprising of a variability of positions within the organisation, were interviewed in the region of the Western Cape. It was found that, although extensive research on the two forms of flexibility have been globally conducted, South African literature, particularly on the part of numerical flexibility, is limited. It is thus believed that this study will present a valuable basis to pursue in further research. Literature that was consulted was found to be supportive of the theoretical notion that South African organisations, in order to be globally competitive, have had to restructure and redefine themselves by ensuring that they make the most efficient and effective use of their human resources. The study found that whilst functional flexibility practices benefit employees in that they experienced increased job satisfaction and job mobility, it was the area of numerical flexibility which raised many dissatisfactions, including those of immense job insecurity and remuneration, both financial and otherwise. The study findings suggest a need for a more comprehensive and employee integrated approach by combining organisational with individual oriented initiatives, and ensuring the trade union's involvement in all facets of functional and numerical flexibility initiatives. The thesis ends with recommendations of various strategies for addressing the concerns of management, employees and the trade union in order to ensure full and proper utilisation of human resources so that the end product, namely job satisfaction, leads to organisational success.
- Full Text:
- Authors: Sela, Ronit
- Date: 2002
- Subjects: Business enterprises -- South Africa -- Case studies , Industrial management -- South Africa
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:3347 , http://hdl.handle.net/10962/d1006149 , Business enterprises -- South Africa -- Case studies , Industrial management -- South Africa
- Description: During this research, an attempt was made to gain an understanding of management and their employees' perceptions regarding functional and numerical flexibility practices within South African organisations. To achieve this, twenty-six people, comprising of a variability of positions within the organisation, were interviewed in the region of the Western Cape. It was found that, although extensive research on the two forms of flexibility have been globally conducted, South African literature, particularly on the part of numerical flexibility, is limited. It is thus believed that this study will present a valuable basis to pursue in further research. Literature that was consulted was found to be supportive of the theoretical notion that South African organisations, in order to be globally competitive, have had to restructure and redefine themselves by ensuring that they make the most efficient and effective use of their human resources. The study found that whilst functional flexibility practices benefit employees in that they experienced increased job satisfaction and job mobility, it was the area of numerical flexibility which raised many dissatisfactions, including those of immense job insecurity and remuneration, both financial and otherwise. The study findings suggest a need for a more comprehensive and employee integrated approach by combining organisational with individual oriented initiatives, and ensuring the trade union's involvement in all facets of functional and numerical flexibility initiatives. The thesis ends with recommendations of various strategies for addressing the concerns of management, employees and the trade union in order to ensure full and proper utilisation of human resources so that the end product, namely job satisfaction, leads to organisational success.
- Full Text:
An exploration of the social worker's role in promoting sustainability of poverty alleviating projects
- Ndude, Peace-Maker Mqokeleli
- Authors: Ndude, Peace-Maker Mqokeleli
- Date: 2002
- Subjects: Poverty -- South Africa , Poor -- Services for -- South Africa , Social service -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:6058 , http://hdl.handle.net/10962/d1006664 , Poverty -- South Africa , Poor -- Services for -- South Africa , Social service -- South Africa
- Description: In this research study the researcher attempted to gain an insight on what constitutes sustainability of poverty alleviating projects. Further, the researcher attempted to explore and gain understanding of the role of social worker in promoting sustainability of poverty alleviating projects. Since the literature on sustainability is limited, it is hoped that this study will provide valuable information for further research on the topic. In the limited literature study undertaken however, it was evident that despite the generic service that they provide, social workers have a role to play in community development. It was found that social workers can no longer afford to restrict their service provision to the traditional methods of social work. The egalitarian nature of their profession demands that they occupy the centre stage in poverty alleviation as they are strategically placed between the poor and the decision-makers in government. Eighteen respondents composed of six social workers, six committee members and six community members from six poverty alleviating projects were interviewed. One project from each of the six districts of Tsomo, Nqamakwe, Butterworth, Centane, Idutywa and Willowvale were used in the research study. The fmdings suggested that social workers, committee members and community members have differing opinions on what promotes or impedes sustainability of poverty alleviating projects, All respondents however agreed that participation as well as empowerment through training were basic requirements towards sustainability of poverty alleviating projects. Again the findings agreed with the literature that social workers have an important role to play in promoting sustainability of poverty alleviating projects.
- Full Text:
- Authors: Ndude, Peace-Maker Mqokeleli
- Date: 2002
- Subjects: Poverty -- South Africa , Poor -- Services for -- South Africa , Social service -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:6058 , http://hdl.handle.net/10962/d1006664 , Poverty -- South Africa , Poor -- Services for -- South Africa , Social service -- South Africa
- Description: In this research study the researcher attempted to gain an insight on what constitutes sustainability of poverty alleviating projects. Further, the researcher attempted to explore and gain understanding of the role of social worker in promoting sustainability of poverty alleviating projects. Since the literature on sustainability is limited, it is hoped that this study will provide valuable information for further research on the topic. In the limited literature study undertaken however, it was evident that despite the generic service that they provide, social workers have a role to play in community development. It was found that social workers can no longer afford to restrict their service provision to the traditional methods of social work. The egalitarian nature of their profession demands that they occupy the centre stage in poverty alleviation as they are strategically placed between the poor and the decision-makers in government. Eighteen respondents composed of six social workers, six committee members and six community members from six poverty alleviating projects were interviewed. One project from each of the six districts of Tsomo, Nqamakwe, Butterworth, Centane, Idutywa and Willowvale were used in the research study. The fmdings suggested that social workers, committee members and community members have differing opinions on what promotes or impedes sustainability of poverty alleviating projects, All respondents however agreed that participation as well as empowerment through training were basic requirements towards sustainability of poverty alleviating projects. Again the findings agreed with the literature that social workers have an important role to play in promoting sustainability of poverty alleviating projects.
- Full Text:
An investigation into multimedia service creation using sip
- Hsieh, M, Okuthe, J, Terzoli, Alfredo, Wentworth, Peter N
- Authors: Hsieh, M , Okuthe, J , Terzoli, Alfredo , Wentworth, Peter N
- Date: 2002
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427533 , vital:72445 , https://www.researchgate.net/profile/Alfredo-Ter-zoli/publication/267852929_An_investigation_into_multimedia_service_creation_using_SIP/links/5523cb990cf2b351d9c338c9/An-investigation-into-multimedia-service-creation-using-SIP.pdf
- Description: This paper investigates two sip architectures and how services creation works in those two environments. The two architectures are SIPCOMM (www. sipcomm. com) and VOCAL (www. vovida. org). As a concrete example we look at how the voicemail service is implemented in both environments and then at how we could implement an alarm service.
- Full Text:
- Authors: Hsieh, M , Okuthe, J , Terzoli, Alfredo , Wentworth, Peter N
- Date: 2002
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427533 , vital:72445 , https://www.researchgate.net/profile/Alfredo-Ter-zoli/publication/267852929_An_investigation_into_multimedia_service_creation_using_SIP/links/5523cb990cf2b351d9c338c9/An-investigation-into-multimedia-service-creation-using-SIP.pdf
- Description: This paper investigates two sip architectures and how services creation works in those two environments. The two architectures are SIPCOMM (www. sipcomm. com) and VOCAL (www. vovida. org). As a concrete example we look at how the voicemail service is implemented in both environments and then at how we could implement an alarm service.
- Full Text:
An investigation into the possible neuroprotective properties of phenytoin
- Authors: Naga, Nishal
- Date: 2002
- Subjects: Phenytoin -- Therapeutic use , Phenytoin -- Physiological effect , Nervous system -- Degeneration -- Prevention
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3780 , http://hdl.handle.net/10962/d1003258 , Phenytoin -- Therapeutic use , Phenytoin -- Physiological effect , Nervous system -- Degeneration -- Prevention
- Description: Cerebral ischaemia, traumatic injury to the brain, inflammatory neurological disorders and HIV infections are amongst the most prevalent causes of neurodegeneration. Neuroprotective strategies are usually to limit the progressive secondary injury that generally occurs, thus limiting overall tissue damage. Neuroprotective strategies are usually to limit the progressive secondary injury that generally occurs, thus limiting overall tissue damage. Sodium channel blockers have been often used for this matter as they prevent the cascade of events culminating in free radical generation and eventually neuronal apoptosis. Newer compounds, such as antiperoxidants and free radical scavengers, show encouraging experimental results, but their clinical use is still very limited. Phenytoin being a popular drug in the treatment of epilepsy has also been used as a neuroprotectant during certain neurological emergencies and in pharmacological prophylaxis of post-traumatic epilepsy. Furthermore this agent functions by prolonging inactivation of voltage gated sodium channels. In these sets of experiment the neuroprotective properties of phenytoin were examined. The histological study revealed that phenytoin confers protection to the CA1 and CA3 regions of the hippocampus under the insult of QUIN. Cells maintain their characteristic shape and minimal tissue necrosis occurs in the presence of this agent. The in vitro effect of this antiepileptic drug on free radicals generation shows that phenytoin does not reduce or prevent the formation of these reactive species. Lipid peroxidation was induced using QUIN and iron (II), two known neurotoxins. The study reveals that only lipid peroxidation induced using iron (II) is reduced by phenytoin. These experiments were carried out in whole rat brain homogenate. These studies show that phenytoin possesses poor free radical scavenging properties. However, the dose-related reduction of iron-induced lipid peroxidation allows for speculation that phenytoin interacts with iron in order to reduce neuronal damage. Metal binding studies were performed using UV, IR and electrochemical analysis to examine the interaction of phenytoin with iron (II) and iron (III). Phenytoin, when added to iron (II) in solution, first oxidises the latter to iron (III) and maintains it in that form. A shift in the peak was observed in the UV spectrum when iron was added to phenytoin. Moreover, electrochemical studies indicate that the interaction between the metal and the ligand is very weak. The IR analysis it shows that phenytoin may be coordinating with iron through the Nitrogen atom on the phenytoin molecule. These studies show that phenytoin maintains iron in its oxidised form, which is a good property to possess as a neuroprotectants. Pineal organ culture showed that phenytoin does not increase melatonin production but slightly and non-significantly reduces the levels of this pineal hormone. However there is a significant rise in precursor NAS levels. As melatonin is known to possess antioxidant and free radical scavenging properties, this could mean that this drug can cause the CNS to become more susceptible to attacks by reactive oxygen species.
- Full Text:
- Authors: Naga, Nishal
- Date: 2002
- Subjects: Phenytoin -- Therapeutic use , Phenytoin -- Physiological effect , Nervous system -- Degeneration -- Prevention
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3780 , http://hdl.handle.net/10962/d1003258 , Phenytoin -- Therapeutic use , Phenytoin -- Physiological effect , Nervous system -- Degeneration -- Prevention
- Description: Cerebral ischaemia, traumatic injury to the brain, inflammatory neurological disorders and HIV infections are amongst the most prevalent causes of neurodegeneration. Neuroprotective strategies are usually to limit the progressive secondary injury that generally occurs, thus limiting overall tissue damage. Neuroprotective strategies are usually to limit the progressive secondary injury that generally occurs, thus limiting overall tissue damage. Sodium channel blockers have been often used for this matter as they prevent the cascade of events culminating in free radical generation and eventually neuronal apoptosis. Newer compounds, such as antiperoxidants and free radical scavengers, show encouraging experimental results, but their clinical use is still very limited. Phenytoin being a popular drug in the treatment of epilepsy has also been used as a neuroprotectant during certain neurological emergencies and in pharmacological prophylaxis of post-traumatic epilepsy. Furthermore this agent functions by prolonging inactivation of voltage gated sodium channels. In these sets of experiment the neuroprotective properties of phenytoin were examined. The histological study revealed that phenytoin confers protection to the CA1 and CA3 regions of the hippocampus under the insult of QUIN. Cells maintain their characteristic shape and minimal tissue necrosis occurs in the presence of this agent. The in vitro effect of this antiepileptic drug on free radicals generation shows that phenytoin does not reduce or prevent the formation of these reactive species. Lipid peroxidation was induced using QUIN and iron (II), two known neurotoxins. The study reveals that only lipid peroxidation induced using iron (II) is reduced by phenytoin. These experiments were carried out in whole rat brain homogenate. These studies show that phenytoin possesses poor free radical scavenging properties. However, the dose-related reduction of iron-induced lipid peroxidation allows for speculation that phenytoin interacts with iron in order to reduce neuronal damage. Metal binding studies were performed using UV, IR and electrochemical analysis to examine the interaction of phenytoin with iron (II) and iron (III). Phenytoin, when added to iron (II) in solution, first oxidises the latter to iron (III) and maintains it in that form. A shift in the peak was observed in the UV spectrum when iron was added to phenytoin. Moreover, electrochemical studies indicate that the interaction between the metal and the ligand is very weak. The IR analysis it shows that phenytoin may be coordinating with iron through the Nitrogen atom on the phenytoin molecule. These studies show that phenytoin maintains iron in its oxidised form, which is a good property to possess as a neuroprotectants. Pineal organ culture showed that phenytoin does not increase melatonin production but slightly and non-significantly reduces the levels of this pineal hormone. However there is a significant rise in precursor NAS levels. As melatonin is known to possess antioxidant and free radical scavenging properties, this could mean that this drug can cause the CNS to become more susceptible to attacks by reactive oxygen species.
- Full Text:
An investigation into the possible neuroprotective role of antidepressant drugs
- Authors: Steiner, Claire
- Date: 2002
- Subjects: Antidepressants -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3792 , http://hdl.handle.net/10962/d1003270 , Antidepressants -- Research
- Description: Antidepressants are widely used in the treatment of depressive illnesses associated with neurodegenerative disorders such as Alzheimer’s disease, Parkinson’s disease and Huntington’s disease. Neuroprotection in such disorders is of vital importance in order to delay the progression of the primary disorder. The pathology of neurodegeneration is not fully understood. It is however widely accepted that oxidative stress and excitotoxicity play a major role. Brain tissue is rich in phospholipids, which are especially prone to oxidation due to the high level of oxygen utilization in the brain. In addition, the brain lacks defence mechanisms to protect it against the wrath of free radicals. Presently, there is a wide variety of antidepressant drugs available. These range from the original tricyclic antidepressants to the newer selective serotonin reuptake inhibitors. It is not known whether antidepressant drugs, old or new, offer neuroprotection or how the existing state and/or the progression of neurodegeneration, is influenced by these agents. The present study was undertaken to determine how nortriptyline, trimipramine and fluoxetine affect neurodegeneration. Initial in vitro and in vivo studies show that all three of the antidepressants (0-1mM) studied provide neuroprotection from quinolinic acid induced lipid peroxidation. A histological investigation supported these findings by showing that a marginal degree of neuroprotection is apparent when treating animals with antidepressants (10mg/kg) before and following quinolinic acid intrastriatal injection. Further studies were undertaken in an attempt to determine the mode of neuroprotective action of the agents studied. An in vitro study of superoxide anion induced lipid peroxidation indicates that these agents do not act as antioxidants. The influence of the antidepressants on tryptophan 2,3-dioxygenase activity was assessed, based on the understanding that inhibition of this enzyme results in increased levels of the known antioxidant indoleamine, melatonin. Nortriptyline hydrochloride is seen to inhibit tryptophan 2,3-dioxygenase activity and as such it is possible that this antidepressant can indirectly provide neuroprotection by increasing available melatonin. Electrochemical and UV/visible studies show that trimipramine maleate interacts with free iron (II) and iron (III) ions. Free metal ions can catalyse the formation of damaging free radicals. Through interaction with trimipramine maleate, these ions will be unavailable to the system and thus cannot contribute to oxidative stress. The findings of this study indicate that antidepressants may be able to provide neuroprotection to neuronal cells. The mode of such neuroprotective actions need to be further examined so that patients suffering from depression coexisting with neurodegenerative diseases can be safely and effectively treated.
- Full Text:
- Authors: Steiner, Claire
- Date: 2002
- Subjects: Antidepressants -- Research
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3792 , http://hdl.handle.net/10962/d1003270 , Antidepressants -- Research
- Description: Antidepressants are widely used in the treatment of depressive illnesses associated with neurodegenerative disorders such as Alzheimer’s disease, Parkinson’s disease and Huntington’s disease. Neuroprotection in such disorders is of vital importance in order to delay the progression of the primary disorder. The pathology of neurodegeneration is not fully understood. It is however widely accepted that oxidative stress and excitotoxicity play a major role. Brain tissue is rich in phospholipids, which are especially prone to oxidation due to the high level of oxygen utilization in the brain. In addition, the brain lacks defence mechanisms to protect it against the wrath of free radicals. Presently, there is a wide variety of antidepressant drugs available. These range from the original tricyclic antidepressants to the newer selective serotonin reuptake inhibitors. It is not known whether antidepressant drugs, old or new, offer neuroprotection or how the existing state and/or the progression of neurodegeneration, is influenced by these agents. The present study was undertaken to determine how nortriptyline, trimipramine and fluoxetine affect neurodegeneration. Initial in vitro and in vivo studies show that all three of the antidepressants (0-1mM) studied provide neuroprotection from quinolinic acid induced lipid peroxidation. A histological investigation supported these findings by showing that a marginal degree of neuroprotection is apparent when treating animals with antidepressants (10mg/kg) before and following quinolinic acid intrastriatal injection. Further studies were undertaken in an attempt to determine the mode of neuroprotective action of the agents studied. An in vitro study of superoxide anion induced lipid peroxidation indicates that these agents do not act as antioxidants. The influence of the antidepressants on tryptophan 2,3-dioxygenase activity was assessed, based on the understanding that inhibition of this enzyme results in increased levels of the known antioxidant indoleamine, melatonin. Nortriptyline hydrochloride is seen to inhibit tryptophan 2,3-dioxygenase activity and as such it is possible that this antidepressant can indirectly provide neuroprotection by increasing available melatonin. Electrochemical and UV/visible studies show that trimipramine maleate interacts with free iron (II) and iron (III) ions. Free metal ions can catalyse the formation of damaging free radicals. Through interaction with trimipramine maleate, these ions will be unavailable to the system and thus cannot contribute to oxidative stress. The findings of this study indicate that antidepressants may be able to provide neuroprotection to neuronal cells. The mode of such neuroprotective actions need to be further examined so that patients suffering from depression coexisting with neurodegenerative diseases can be safely and effectively treated.
- Full Text:
An investigation into the viability of deploying thin client technology to support effective learning in a disadvantaged, rural high school setting
- Authors: Ndwe, Tembalethu Jama
- Date: 2002
- Subjects: Network computers , Education -- Data processing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4627 , http://hdl.handle.net/10962/d1006500 , Network computers , Education -- Data processing
- Description: Computer Based Training offers many attractive learning opportunities for high school pupils. Its deployment in economically depressed and educationally marginalized rural schools is extremely uncommon due to the high technology skills and costs involved in its deployment and ongoing maintenance. This thesis puts forward thin client technology as a potential solution to the needs of education environments of this kind. A functional business case is developed and evaluated in this thesis, based upon a requirements analysis of media delivery in learning, and upon formal cost/performance models and a deployment field trial. Because of the economic constraints of the envisaged deployment area in rural education, an industrial field trial is used, and the aspects of this trial that can be carried over to the rural school situation have been used to assess performance and cost indicators. Our study finds that thin client technology could be deployed and maintained more cost effectively than conventional fat client solutions in rural schools, that it is capable of supporting the learning elements needed in this deployment area, and that it is able to deliver the predominantly text based applications currently being used in schools. However, we find that technological improvements are needed before future multimediaintensive applications can be adequately supported.
- Full Text:
- Authors: Ndwe, Tembalethu Jama
- Date: 2002
- Subjects: Network computers , Education -- Data processing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4627 , http://hdl.handle.net/10962/d1006500 , Network computers , Education -- Data processing
- Description: Computer Based Training offers many attractive learning opportunities for high school pupils. Its deployment in economically depressed and educationally marginalized rural schools is extremely uncommon due to the high technology skills and costs involved in its deployment and ongoing maintenance. This thesis puts forward thin client technology as a potential solution to the needs of education environments of this kind. A functional business case is developed and evaluated in this thesis, based upon a requirements analysis of media delivery in learning, and upon formal cost/performance models and a deployment field trial. Because of the economic constraints of the envisaged deployment area in rural education, an industrial field trial is used, and the aspects of this trial that can be carried over to the rural school situation have been used to assess performance and cost indicators. Our study finds that thin client technology could be deployed and maintained more cost effectively than conventional fat client solutions in rural schools, that it is capable of supporting the learning elements needed in this deployment area, and that it is able to deliver the predominantly text based applications currently being used in schools. However, we find that technological improvements are needed before future multimediaintensive applications can be adequately supported.
- Full Text:
An investigation of the management and leadership experiences of female school principals in the Ondangwa education regions
- Authors: Udjombala, Maria
- Date: 2002
- Subjects: Women school principals -- Namibia -- Ondangwa Educational leadership -- Namibia -- Ondangwa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1653 , http://hdl.handle.net/10962/d1003536
- Description: This study explores practical school leadership and management, as enacted by women. The study, conducted in an interpretive paradigm, attempts to gain an understanding of women’s subjective experiences of school leadership and management. Two women principals from Ondangwa West Educational Region were interviewed. The two were selected through consultations with one of the senior inspectors in the region. Both had been principals for more than ten years and were seen by those who are concerned with their school to be successful. The study found that these women prefer a participative style of leadership and management, characterised by consultations with others, teamwork, collaborative decision-making and the use of power to empower others. They also strive for good human relationships because they believe that it fosters mutual respect, trust, openness and a good working atmosphere. All these human centred approaches are directed towards creating a school atmosphere that is conducive to teaching and learning and therefore result in effective schooling and quality educational outcomes. They do not experience gender discrimination in their work places. They have the full support of their supervisors. Though both are married with children, these dual roles do not prevent them from being successful in their professional work. In fact they have reached a stage where they feel confident as leaders and feel that they are acting as role models for fellow women principals and those aspiring to this position. The study concludes that the styles of leadership and management displayed by women are similar to those that are universally accepted as characteristics needed for effective school management and leadership. Though these leadership styles are traditionally associated with women, these characteristics are not gender specific. Therefore it will be in the best interest of schools, if school principals, both men and women, could borrow from these qualities in order to change schools from authoritarian to more democratic institutions.
- Full Text:
- Authors: Udjombala, Maria
- Date: 2002
- Subjects: Women school principals -- Namibia -- Ondangwa Educational leadership -- Namibia -- Ondangwa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1653 , http://hdl.handle.net/10962/d1003536
- Description: This study explores practical school leadership and management, as enacted by women. The study, conducted in an interpretive paradigm, attempts to gain an understanding of women’s subjective experiences of school leadership and management. Two women principals from Ondangwa West Educational Region were interviewed. The two were selected through consultations with one of the senior inspectors in the region. Both had been principals for more than ten years and were seen by those who are concerned with their school to be successful. The study found that these women prefer a participative style of leadership and management, characterised by consultations with others, teamwork, collaborative decision-making and the use of power to empower others. They also strive for good human relationships because they believe that it fosters mutual respect, trust, openness and a good working atmosphere. All these human centred approaches are directed towards creating a school atmosphere that is conducive to teaching and learning and therefore result in effective schooling and quality educational outcomes. They do not experience gender discrimination in their work places. They have the full support of their supervisors. Though both are married with children, these dual roles do not prevent them from being successful in their professional work. In fact they have reached a stage where they feel confident as leaders and feel that they are acting as role models for fellow women principals and those aspiring to this position. The study concludes that the styles of leadership and management displayed by women are similar to those that are universally accepted as characteristics needed for effective school management and leadership. Though these leadership styles are traditionally associated with women, these characteristics are not gender specific. Therefore it will be in the best interest of schools, if school principals, both men and women, could borrow from these qualities in order to change schools from authoritarian to more democratic institutions.
- Full Text:
An investigation of the neuroprotective effects of estrogen in a model of quinolinic acid-induced neurodegeneration
- Authors: Heron, Paula Michelle
- Date: 2002
- Subjects: Estrogen , Quinolinic acid , Nervous system -- Degeneration
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3759 , http://hdl.handle.net/10962/d1003237 , Estrogen , Quinolinic acid , Nervous system -- Degeneration
- Description: The hippocampus, located in the medial temporal lobe, is an important region of the brain responsible for the formation of memory. Thus, any agent that induces stress in this area has detrimental effects and could lead to various types of dementia. Such agents include the neurotoxin, Quinolinic acid. Quinolinic acid (QUIN) is a neurotoxic metabolite of the tryptophan-kynurenine pathway and is an endogenous glutamate agonist that selectively injures and kills vulnerable neurons via the activation of the NMDA class of excitatory amino acid receptors. Estrogen is a female hormone that is responsible for reproduction. However, in the last decade estrogen has been shown to exhibit a wide range of actions on the brain, including neuroprotection. Estrogen has been shown to exhibit intrinsic antioxidant activity and protects cultured neurons against oxidative cell death. This is achieved by estrogen’s ability to scavenge free radicals, which is dependent on the presence of the hydroxyl group at the C3 position on the A ring of the steroid molecule. Numerous studies have shown that estrogen protects neurons against various toxic substances and may play a role in delaying the onset of neurodegenerative diseases, such as Alzheimer’s disease. Neuronal damage due to oxidative stress has been implicated in several neurodegenerative disorders. The detection and measurement of lipid peroxidation is the evidence most frequently cited to support the involvement of free radical reactions in toxicology and in human disease. The study aims to elucidate and further characterise the mechanism behind estrogen’s neuroprotection, using QUIN as a model of neurotoxicity. Initial studies confirm estrogen’s ability to scavenge potent free radicals. In addition, the results show that estrogen forms an interaction with iron (II) and also acts at the NMDA receptor as an agonist. Both mechanisms reduce the ability of QUIN to cause damage to neurons, since QUIN-induced toxicity is dependent on the activation of the NMDA receptor and the formation of a complex with iron (II) to induce lipid peroxidation. Heat shock proteins, especially Hsp 70 play a role in cytoprotection by capturing denatured proteins and facilitating the refolding of these proteins once the stress has been relieved. Estrogen has been shown to increase the level of expression of Hsp70, both inducible and cognate forms of the protein. This suggests that estrogen helps to protect against cellular protein damage induced by any form of stress the cell may encounter. The discovery of neuroprotective agents, such as estrogen, is becoming important as accumulating evidence indicates a protective role in vivo. Thus further research may favour the use of these agents in the treatment of several neurodegenerative disorders. Considering how devastating diseases, such as Alzheimer’s disease, are to a patient and the patient’s families, the discovery of new protective agents are a matter of urgency.
- Full Text:
- Authors: Heron, Paula Michelle
- Date: 2002
- Subjects: Estrogen , Quinolinic acid , Nervous system -- Degeneration
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3759 , http://hdl.handle.net/10962/d1003237 , Estrogen , Quinolinic acid , Nervous system -- Degeneration
- Description: The hippocampus, located in the medial temporal lobe, is an important region of the brain responsible for the formation of memory. Thus, any agent that induces stress in this area has detrimental effects and could lead to various types of dementia. Such agents include the neurotoxin, Quinolinic acid. Quinolinic acid (QUIN) is a neurotoxic metabolite of the tryptophan-kynurenine pathway and is an endogenous glutamate agonist that selectively injures and kills vulnerable neurons via the activation of the NMDA class of excitatory amino acid receptors. Estrogen is a female hormone that is responsible for reproduction. However, in the last decade estrogen has been shown to exhibit a wide range of actions on the brain, including neuroprotection. Estrogen has been shown to exhibit intrinsic antioxidant activity and protects cultured neurons against oxidative cell death. This is achieved by estrogen’s ability to scavenge free radicals, which is dependent on the presence of the hydroxyl group at the C3 position on the A ring of the steroid molecule. Numerous studies have shown that estrogen protects neurons against various toxic substances and may play a role in delaying the onset of neurodegenerative diseases, such as Alzheimer’s disease. Neuronal damage due to oxidative stress has been implicated in several neurodegenerative disorders. The detection and measurement of lipid peroxidation is the evidence most frequently cited to support the involvement of free radical reactions in toxicology and in human disease. The study aims to elucidate and further characterise the mechanism behind estrogen’s neuroprotection, using QUIN as a model of neurotoxicity. Initial studies confirm estrogen’s ability to scavenge potent free radicals. In addition, the results show that estrogen forms an interaction with iron (II) and also acts at the NMDA receptor as an agonist. Both mechanisms reduce the ability of QUIN to cause damage to neurons, since QUIN-induced toxicity is dependent on the activation of the NMDA receptor and the formation of a complex with iron (II) to induce lipid peroxidation. Heat shock proteins, especially Hsp 70 play a role in cytoprotection by capturing denatured proteins and facilitating the refolding of these proteins once the stress has been relieved. Estrogen has been shown to increase the level of expression of Hsp70, both inducible and cognate forms of the protein. This suggests that estrogen helps to protect against cellular protein damage induced by any form of stress the cell may encounter. The discovery of neuroprotective agents, such as estrogen, is becoming important as accumulating evidence indicates a protective role in vivo. Thus further research may favour the use of these agents in the treatment of several neurodegenerative disorders. Considering how devastating diseases, such as Alzheimer’s disease, are to a patient and the patient’s families, the discovery of new protective agents are a matter of urgency.
- Full Text:
Aphid (Sitobion yakini) investigation shows thin-walled sieve tubes in barley (Hordeum vulgare L) to be more functional than thick-walled sieve tubes
- Matsiliza, Balbalwa, Botha, Christiaan E J
- Authors: Matsiliza, Balbalwa , Botha, Christiaan E J
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6526 , http://hdl.handle.net/10962/d1005960
- Description: Barley, like most other grasses that have been studied, contains two kinds of sieve tube. The first formed are called thinwalled sieve tubes because of their thin wall compared to the late-formed, and are associated with companion cells. The late-formed are thick-walled sieve tubes, which differentiate next to the metaxylem vessels and lack companion cells. Aphid (Sitobion yakini (Eastop) feeding was studied using light microscopy to determine if they preferentially feed from thin- or thick-walled sieve tubes in the barley leaf. Penetration of the stylets through the leaf epidermis and mesophyll was largely intercellular, becoming partly intercellular and, partly, intracellular inside the vascular bundle. Sixteen of 19 pairs of stylets (84%), and 293 of 317 (92%) stylet tracks terminated at the thin-walled sieve tubes, suggesting that Sitobion yakini feeds preferentially on the thin-walled sieve tubes which seem to be more attractive to the aphid. These thin-walled sieve tubes are thus probably the most functional in terms of phloem loading and transport.
- Full Text:
- Authors: Matsiliza, Balbalwa , Botha, Christiaan E J
- Date: 2002
- Language: English
- Type: Article
- Identifier: vital:6526 , http://hdl.handle.net/10962/d1005960
- Description: Barley, like most other grasses that have been studied, contains two kinds of sieve tube. The first formed are called thinwalled sieve tubes because of their thin wall compared to the late-formed, and are associated with companion cells. The late-formed are thick-walled sieve tubes, which differentiate next to the metaxylem vessels and lack companion cells. Aphid (Sitobion yakini (Eastop) feeding was studied using light microscopy to determine if they preferentially feed from thin- or thick-walled sieve tubes in the barley leaf. Penetration of the stylets through the leaf epidermis and mesophyll was largely intercellular, becoming partly intercellular and, partly, intracellular inside the vascular bundle. Sixteen of 19 pairs of stylets (84%), and 293 of 317 (92%) stylet tracks terminated at the thin-walled sieve tubes, suggesting that Sitobion yakini feeds preferentially on the thin-walled sieve tubes which seem to be more attractive to the aphid. These thin-walled sieve tubes are thus probably the most functional in terms of phloem loading and transport.
- Full Text:
Aspects pertinent to the provision of sustainable water supply projects in the Eastern Cape Province: a case study of Nomzamo Water Supply Project
- Authors: Mpendu, Daluhlanga Ayford
- Date: 2002
- Subjects: Water-supply -- South Africa -- Eastern Cape Nomzamo Water Supply Project Water-supply -- South Africa -- Social aspects
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:5952 , http://hdl.handle.net/10962/d1007450
- Description: This study explores views behind the failure of water supply projects to achieve sustainability, primarily from the 'users' perspective, and at a secondary level from the perspective of the government/funders. One completed water supply project was selected as a case study for the research project. The overriding principle behind the water infrastructure delivery programme is that the service must be provided in a sustainable manner, and that the community must actively participate and be involved in all the phases of the project. The provision of water is not simply as it might look. In reality it is a complex process, which involves a number of organisations with different, yet important roles and responsibilities. Ongoing collaboration is important among these organisations if the service is to be provided efficiently and in a sustainable manner. In particular, local government has a Constitutional obligation to provide services to all consumers in an efficient, affordable, economical and sustainable manner. The National and Provincial governments, however, have a number of responsibilities in the field of water services. Semi-structured interview method was used to collect data from respondents. Two sets of interview schedules were developed, one for the community/water project committee members, and the other for the government officials. The data collected was analysed both qualitatively and quantitatively. This analysis enabled the researcher to draw findings, make conclusions and propose recommendations. The findings and conclusions of the study point to lack of clarity on roles and responsibilities; gender and cultural constraints; and, poor training and capacity and building of the community as being some of the reasons for the failure of the project. The recommendations proposed entail, inter alia, massive community mobilisation and awareness creation programmes; improvement in levels of the service; adoption of a gender-sensitive approach to project development; and, implementation of a training and capacity building process in the community in order to 'revitalise' the project. The study has merely focussed on one water project and sets the scene for further exploration of the subject. It certainly highlights some critical issues around sustainability of water projects, and hopefully will contribute towards the ongoing debate in this area.
- Full Text:
- Authors: Mpendu, Daluhlanga Ayford
- Date: 2002
- Subjects: Water-supply -- South Africa -- Eastern Cape Nomzamo Water Supply Project Water-supply -- South Africa -- Social aspects
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:5952 , http://hdl.handle.net/10962/d1007450
- Description: This study explores views behind the failure of water supply projects to achieve sustainability, primarily from the 'users' perspective, and at a secondary level from the perspective of the government/funders. One completed water supply project was selected as a case study for the research project. The overriding principle behind the water infrastructure delivery programme is that the service must be provided in a sustainable manner, and that the community must actively participate and be involved in all the phases of the project. The provision of water is not simply as it might look. In reality it is a complex process, which involves a number of organisations with different, yet important roles and responsibilities. Ongoing collaboration is important among these organisations if the service is to be provided efficiently and in a sustainable manner. In particular, local government has a Constitutional obligation to provide services to all consumers in an efficient, affordable, economical and sustainable manner. The National and Provincial governments, however, have a number of responsibilities in the field of water services. Semi-structured interview method was used to collect data from respondents. Two sets of interview schedules were developed, one for the community/water project committee members, and the other for the government officials. The data collected was analysed both qualitatively and quantitatively. This analysis enabled the researcher to draw findings, make conclusions and propose recommendations. The findings and conclusions of the study point to lack of clarity on roles and responsibilities; gender and cultural constraints; and, poor training and capacity and building of the community as being some of the reasons for the failure of the project. The recommendations proposed entail, inter alia, massive community mobilisation and awareness creation programmes; improvement in levels of the service; adoption of a gender-sensitive approach to project development; and, implementation of a training and capacity building process in the community in order to 'revitalise' the project. The study has merely focussed on one water project and sets the scene for further exploration of the subject. It certainly highlights some critical issues around sustainability of water projects, and hopefully will contribute towards the ongoing debate in this area.
- Full Text:
Assessing the need for specific services for HIV/AIDS affected people using participatory needs assessment processes
- Authors: Moresby-White, Ann
- Date: 2002
- Subjects: AIDS (Disease) -- Patients -- Services for , HIV-positive persons -- Services for , AIDS (Disease) -- Research , AIDS (Disease) -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:713 , http://hdl.handle.net/10962/d1007692 , AIDS (Disease) -- Patients -- Services for , HIV-positive persons -- Services for , AIDS (Disease) -- Research , AIDS (Disease) -- South Africa
- Description: The purpose of the study undertaken is to develop knowledge to assist service providers in their planning and implementation of community -based programmes and projects. The thesis explores the most appropriate way of conducting a needs assessment, relating to HIV/AIDS services in a particular community; thereafter the needs assessment was carried out. This qualitative research study is conducted using participatory methods and techniques. The research reviews literature pertaining to HIV/AIDS, specifically in Africa, South Africa and the Eastern Cape and incorporates a discussion on the concept of community, community development and poverty. The design of the needs assessment tool, implementation and analysis is conducted through focus group discussions and individual semi-structured interviews. The theory on participatory approaches and community development are central to this study. The study found that HIV / AIDS as an issue is not perceived by the community under study to be an immediate need in light of basic needs being identified as priority. The use of participatory methods in this study highlighted the diversity within communities. Service providers who wish to initiate community - based projects need to take note of diversity and personal interests of individuals or groups who become involved in community- based projects. The study further highlighted the need for service providers to provide training, to their staff in participatory approaches and techniques, before embarking on community development projects. The study concludes that services relating to the HIV/AIDS epidemic cannot be carried out in isolation, but that an integrated approach is needed in the planning and implementation of services and programmes to address those affected by HIV/AIDS.
- Full Text:
- Authors: Moresby-White, Ann
- Date: 2002
- Subjects: AIDS (Disease) -- Patients -- Services for , HIV-positive persons -- Services for , AIDS (Disease) -- Research , AIDS (Disease) -- South Africa
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:713 , http://hdl.handle.net/10962/d1007692 , AIDS (Disease) -- Patients -- Services for , HIV-positive persons -- Services for , AIDS (Disease) -- Research , AIDS (Disease) -- South Africa
- Description: The purpose of the study undertaken is to develop knowledge to assist service providers in their planning and implementation of community -based programmes and projects. The thesis explores the most appropriate way of conducting a needs assessment, relating to HIV/AIDS services in a particular community; thereafter the needs assessment was carried out. This qualitative research study is conducted using participatory methods and techniques. The research reviews literature pertaining to HIV/AIDS, specifically in Africa, South Africa and the Eastern Cape and incorporates a discussion on the concept of community, community development and poverty. The design of the needs assessment tool, implementation and analysis is conducted through focus group discussions and individual semi-structured interviews. The theory on participatory approaches and community development are central to this study. The study found that HIV / AIDS as an issue is not perceived by the community under study to be an immediate need in light of basic needs being identified as priority. The use of participatory methods in this study highlighted the diversity within communities. Service providers who wish to initiate community - based projects need to take note of diversity and personal interests of individuals or groups who become involved in community- based projects. The study further highlighted the need for service providers to provide training, to their staff in participatory approaches and techniques, before embarking on community development projects. The study concludes that services relating to the HIV/AIDS epidemic cannot be carried out in isolation, but that an integrated approach is needed in the planning and implementation of services and programmes to address those affected by HIV/AIDS.
- Full Text:
Asthenospheric and lithospheric sources for Mesozoic dolerites from Liberia (Africa): trace element and isotopic evidence
- Dupuy, C, Marsh, Julian S, Dostal, J, Michard, A, Testa, S
- Authors: Dupuy, C , Marsh, Julian S , Dostal, J , Michard, A , Testa, S
- Date: 2002
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140422 , vital:37887 , https://doi.org/10.1016/0012-821X(88)90067-2
- Description: Combined elemental, and Sr and Nd isotopic data are presented for Mesozoic dolerite dikes of Liberia (Africa) which are related to the initial stage of opening of the Atlantic Ocean.
- Full Text: false
- Authors: Dupuy, C , Marsh, Julian S , Dostal, J , Michard, A , Testa, S
- Date: 2002
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140422 , vital:37887 , https://doi.org/10.1016/0012-821X(88)90067-2
- Description: Combined elemental, and Sr and Nd isotopic data are presented for Mesozoic dolerite dikes of Liberia (Africa) which are related to the initial stage of opening of the Atlantic Ocean.
- Full Text: false
Bad faith: the psychological life of a satanist who committed murder
- Authors: Du Toit, Jacobus Petrus
- Date: 2002
- Subjects: Murderers -- Psychology , Criminal psychology , Satanism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3152 , http://hdl.handle.net/10962/d1007483 , Murderers -- Psychology , Criminal psychology , Satanism
- Description: Traditional methods of psychological and forensic research fail to adequately provide an account of the psychological meaning that perpetrators of crime derive when appropriating their actions to Satanic involvement. In February 2001, a young man appeared in a South African High Court and testified that he had committed murder as a result of his involvement in Satanism. The aim of this study is to gain a phenomenological understanding of how this man appropriates the act of murder to involvement in Satanism. A review of literature elucidates Satanism as a context for meaning, provide a framework for defining murder as a criminal act, and situate this study in the broader field of phenomenological-existential, psychological research. An emergent design case-study approach was applied to data gathered from a single subject, by means of a three-interview series. An empirical phenomenological methodology was used during the interpretive phase to arrive at both a descriptive account of the subject's phenomenological experience and how the eidetic structure of the experience of Satanism as a context tor meaning emerged. A discussion of the subject's appropriation of murder with Satanism illustrates how the subject imposed a dichotomy of good and bad on his life-world in an attempt to derive meaning from his experience of inadequacy. Involvement with Satanism is meaningful, in that it affords its followers an increased sense of power, a safe environment to explore individuality, shared responsibility associated with exercising free choice, social situatedness and an affirmation of being through an increased awareness of finitude. The research subject experienced committing murder as an act of loyalty to the perceived gains he had been afforded as result of his involvement with Satanism.
- Full Text:
- Authors: Du Toit, Jacobus Petrus
- Date: 2002
- Subjects: Murderers -- Psychology , Criminal psychology , Satanism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3152 , http://hdl.handle.net/10962/d1007483 , Murderers -- Psychology , Criminal psychology , Satanism
- Description: Traditional methods of psychological and forensic research fail to adequately provide an account of the psychological meaning that perpetrators of crime derive when appropriating their actions to Satanic involvement. In February 2001, a young man appeared in a South African High Court and testified that he had committed murder as a result of his involvement in Satanism. The aim of this study is to gain a phenomenological understanding of how this man appropriates the act of murder to involvement in Satanism. A review of literature elucidates Satanism as a context for meaning, provide a framework for defining murder as a criminal act, and situate this study in the broader field of phenomenological-existential, psychological research. An emergent design case-study approach was applied to data gathered from a single subject, by means of a three-interview series. An empirical phenomenological methodology was used during the interpretive phase to arrive at both a descriptive account of the subject's phenomenological experience and how the eidetic structure of the experience of Satanism as a context tor meaning emerged. A discussion of the subject's appropriation of murder with Satanism illustrates how the subject imposed a dichotomy of good and bad on his life-world in an attempt to derive meaning from his experience of inadequacy. Involvement with Satanism is meaningful, in that it affords its followers an increased sense of power, a safe environment to explore individuality, shared responsibility associated with exercising free choice, social situatedness and an affirmation of being through an increased awareness of finitude. The research subject experienced committing murder as an act of loyalty to the perceived gains he had been afforded as result of his involvement with Satanism.
- Full Text: